#pragma once

#include "index.hpp"
#include "util.hpp"
#include <algorithm>
#include <unordered_map>
#include <jsoncpp/json/json.h>
#include "log.hpp"

namespace ns_searcher{
    struct InvertedElemPrint{
        uint64_t doc_id;
        int weight;
        std::vector<std::string> words;
        InvertedElemPrint():doc_id(0), weight(0){}
    };
    class Searcher
    {
        private:
        ns_index::Index* index;
        public:
        Searcher(){}
        ~Searcher(){}
        void InitSearcher(const std::string &input)
        {
            //获取单例
            index = ns_index::Index::GetInstance();
            // std::cout<<"获取index单例成功..."<<std::endl;
            LOG(NORMAL, "获取index单例成功...");
            //构建索引
            index->BuildIndex(input);
            // std::cout << "建立正排和倒排索引成功..." << std::endl;
            LOG(NORMAL, "建立正排和倒排索引成功...");
        }
        void Search(const std::string &query,std::string *json_string)
        {
            std::vector<std::string> words;
            ns_util::JiebaUtil::CutString(query,&words);
            // ns_index::InvertedList inverted_list_all;
            std::vector<InvertedElemPrint> inverted_list_all;
            std::unordered_map<uint64_t, InvertedElemPrint> tokens_map;
            for(std::string word:words)
            {
                boost::to_lower(word);

                ns_index::InvertedList* inverted_list = index->GetInvertedLise(word);
                if(inverted_list==nullptr)
                {
                    continue;
                }

                //inverted_list_all.insert(inverted_list_all.end(),inverted_list->begin(),inverted_list->end());
                for(const auto& elem : *inverted_list)
                {
                    auto& item = tokens_map[elem.doc_id];
                    item.doc_id = elem.doc_id;
                    item.weight+=elem.weight;
                    item.words.push_back(elem.word);
                }
            }
            for(const auto& item:tokens_map)
            {
                inverted_list_all.push_back(std::move(item.second));
            }
            //排序查找结果
            //std::sort(inverted_list_all.begin(),inverted_list_all.end(),[](const ns_index::InvertedElem &e1, const ns_index::InvertedElem &e2){return e1.weight > e2.weight;});
            std::sort(inverted_list_all.begin(), inverted_list_all.end(),\
                        [](const InvertedElemPrint &e1, const InvertedElemPrint &e2){
                        return e1.weight > e2.weight;
                        });
            Json::Value root;
            for(auto& item:inverted_list_all)
            {
                ns_index::DocInfo* doc = index->GetForwardList(item.doc_id);
                if(nullptr == doc)
                {
                    continue;
                }
                Json::Value elem;

                elem["title"] = doc->title;
                elem["desc"] = GetDesc(doc->content, item.words[0]); //content是文档的去标签的结果，但是不是我们想要的，我们要的是一部分 TODO
                elem["url"]  = doc->url;
                    //for deubg, for delete
                elem["id"] = (int)item.doc_id;
                elem["weight"] = item.weight; //int->string

                root.append(elem);
            }

            // Json::FastWriter writer;
            Json::StyledWriter writer;
            *json_string = writer.write(root);

        }
        std::string GetDesc(const std::string &html_content, const std::string &word)
            {
                //找到word在html_content中的首次出现，然后往前找50字节(如果没有，从begin开始)，往后找100字节(如果没有，到end就可以的)
                //截取出这部分内容
                const int prev_step = 50;
                const int next_step = 100;
                //1. 找到首次出现
                auto iter = std::search(html_content.begin(), html_content.end(), word.begin(), word.end(), [](int x, int y){
                        return (std::tolower(x) == std::tolower(y));
                        });
                if(iter == html_content.end()){
                    return "None1";
                }
                int pos = std::distance(html_content.begin(), iter);

                //2. 获取start，end , std::size_t 无符号整数
                int start = 0; 
                int end = html_content.size() - 1;
                //如果之前有50+字符，就更新开始位置
                if(pos > start + prev_step) start = pos - prev_step;
                if(pos < end - next_step) end = pos + next_step;

                //3. 截取子串,return
                if(start >= end) return "None2";
                std::string desc = html_content.substr(start, end - start);
                desc += "...";
                return desc;
            }
    };
}